FIVE WAYS GREEN BUILDINGS SAVE WATER
National Water Week takes place in South Africa from 20 March with the aim of educating the public and industry about their responsibility in water conservation initiatives and raising awareness around the need to protect and conserve the country’s valuable water resources.
While historically there has been a pattern of unsustainable water use in the built environment, today’s green buildings are leading the way in water conservation, as they integrate water-efficient technologies in their design, construction and living strategies. Here are some examples of green building features that can help save water:
- What you measure, you can manage
Most green buildings have submeters to monitor and regulate water usage. These devices are particularly important in identifying any leaks, with early detection leading to potentially huge water savings. Those who oversee the maintenance of the building are responsible for tracking water data, with additional benefits available if select information, such as the amount of water used in a period, is displayed in places where people use water. This is in line with what is known as the Prius Effect, which states that when presented with information, people tend to have a greater incentive to reduce consumption. Buildings that incorporate sustainable features commonly have a display board in a central location for occupants to familiarise themselves with the purpose of the mechanisms in place and how they work to reduce carbon footprint. This knowledge is critical in creating a culture of awareness, which ultimately enables responsible citizenship.
- Less pressure, greater water efficiency
Green buildings that are fitted with water-efficient plumbing fixtures in bathrooms, kitchens and other spaces where water flows provide a range of benefits. They can produce substantial water savings (typically 40% to 60%), so that water can be saved for future consumption; they reduce wastage and bring down water and energy (for heating) costs; and they ensure that the water supply that is required throughout the building is maintained. Replacing older water fixtures with low-flow aerators and restrictors does not require any extensive design solutions, and is a relatively low-cost way to conserve water and save money. Pressure-reducing valves, also known as PRVs, can be set on the main water line to reduce water pressure, while still maintaining adequate flow. These valves have the added benefit of expanding the lifespan of the pipes. Many corporate green buildings have showers for employees to use if they have cycled to work; once again, the utilisation of low-flow shower heads can increase water efficiency.
- Think before you flush
As many as 40% of toilets are older models with a syphon-flushing system that holds between 9 litres to 15 litres of water and drains the entire cistern for each flush. Water-efficient sanitaryware, such as hold-flush toilets, can result in substantial savings, both in water and cost. Newer, more efficient models, which are used in green buildings, can reduce the number to about six litres per flush, through design changes that implement gravity and air pressure to remove waste from the toilet without having to use as much water. A hold-flush system is another water-efficient variant that lets the user control the flush volume – as soon as one lets go of the toilet handle it will stop flushing. This can save more than 50% of the flushing volume. Other options include waterless urinals, which, while viable, are not that popular because they require the addition of a specific liquid. A low-flow urinal seems to be a better compromise at this stage.
- A drought-proof garden
Many green buildings are leading the way with “xeriscaped” gardens – landscapes that are water-wise due to the way in which they are designed, as well as in the choice of plants used. The practice reduces maintenance costs as well as water utility bills, and has a number of other additional benefits. These include a minimised demand for fertiliser, as xeriscaping encourages the use of organic soil, which can in time reduce pollution on a wider scale. Green buildings place a big focus on incorporating nature into their spaces, due to the proven benefits of biophilia (the connection that exists between humans and nature).
Landscape architects are able to design spaces that make use of indigenous plants, which naturally require less water, while still ensuring a lush feel. Green walls and other innovative designs are helpful in “bringing the outdoors indoors”.
- Grey is the new black
Green buildings are renowned for their rainwater harvesting techniques, as well as the use of grey water and recycled water. While these water sources are not for drinking, they can be used in a variety of ways, from flushing toilets and doing laundry, through to basin water. With the use of non-potable water, a building’s residents can reduce their dependency on municipal supply, and also get them involved in the process of learning more about water treatment, reuse, and the benefits of using treated water for daily non-consumption purposes. Provided that no harsh chemicals have gone into the water, grey water can also be effectively used to water plants and keep “living walls” alive.
While the building industry is responsible for a large percentage of water use, the fact that green buildings have invested substantially into being water-wise has had the positive impact of making these water-saving features become more mainstream. Costs have been reduced, and, most importantly, the average mindset is moving away from one where water is seen as being an eternal supply available in abundance, to the more accurate view that it needs to be carefully conserved for future generations.